1. Field of the Invention
The present invention relates to an automatic door system of controlling the opening and closing of an automatic door by the presence or absence of a passerby. The invention further relates to a method for controlling an automatic door.
2. Description of Prior Art
FIG. 28 is a schematic diagram of the structure of a conventional automatic door system. An ultrasonic sensor 102 emits ultrasonic waves toward a floor face 103 in the vicinity of the entrance of an automatic door 101. The ultrasonic sensor 102 has a function to detect reflected waves of the emitted ultrasonic waves and to measure a distance between an object reflecting the ultrasonic waves (hereinafter referred to as a xe2x80x9creflecting objectxe2x80x9d) and itself.
When no passer such as a passerby or a vehicle (hereinafter represented by a passerby) is in the vicinity of the entrance of the automatic door 101, the ultrasonic waves emitted from the ultrasonic sensor 102 is reflected from the floor face 103. Detecting the reflected waves, the ultrasonic sensor 102 measures a distance between the reflecting object and itself. A distance between the ultrasonic sensor 102 and the floor face 103 has previously been taught to the ultrasonic sensor 102. When the reflecting object is the floor face 103, the measured distance agrees with the teaching distance. Thus, the ultrasonic sensor 102 identifies the reflecting object as the floor face 103, and judges that no passerby is in the vicinity of the entrance of the automatic door 101. In this case, the ultrasonic sensor 102 does not perform an opening operation of the automatic door 101.
When a passerby approaches the entrance of the automatic door 101, on the other hand, the ultrasonic waves from the ultrasonic sensor 102 are reflected from that passerby. Detecting the reflected waves, the ultrasonic sensor 102 measures a distance between the reflecting object and itself. In this case, the measured distance disagrees with the teaching distance. Thus, the ultrasonic sensor 102 identifies the reflecting object as something other than the floor face 103, and judges that a passerby is in the vicinity of the entrance of the automatic door 101. The ultrasonic sensor 102 then performs the opening operation of the automatic door 101.
In this conventional automatic door system, the distance between the ultrasonic sensor 102 and the reflecting object is measured by detecting the reflected waves from the reflecting object. The measured distance is then compared with the teaching distance to determine whether to perform the opening operation of the automatic door 101 or not. This system, however, has several shortcomings as follows:
First, when a stationary object such as a wall or a screen other than the floor face 103 is placed in the vicinity of the entrance of the automatic door 101, the ultrasonic waves emitted from the ultrasonic sensor 102 are reflected from the stationary object. This reduces a distance between the ultrasonic sensor 102 and the reflecting object, thereby making the measured distance different from the teaching distance. Accordingly, the automatic door 101 is left open or opened and closed repeatedly.
Second, the ultrasonic sensor 102 detects the reflected waves from a passerby even when the passerby just passes by the entrance of the automatic door 101, and performs the opening operation of the automatic door 101.
A first aspect of the present invention is directed to an automatic door system comprising: a passable door for a movable passer; and a control portion for detecting a direction that the passer faces with respect to the door and determining whether to allow the passer to pass through the door or not on the basis of the direction.
According to a second aspect of the present invention, in the automatic door system of the first aspect, the passer is movable in a direction at least having either component of first and second axes which are orthogonal to each other; the passer is capable of passing through the door in a direction along the first axis; and the control portion measures a width of the passer along the second axis to detect a direction that the passer faces with respect to the door on the basis of the width.
According to a third aspect of the present invention, in the automatic door system of the first aspect, the passer is movable in a direction at least having either component of first and second axes which are orthogonal to each other; the passer is capable of passing through the door in a direction along the first axis; and the control portion obtains a projection of the passer with respect to a fourth axis to detect a direction that the passer faces with respect to the door on the basis of variance of the projection, the fourth axis having a component of the first axis and a component of a third axis which is orthogonal to both of the first and second axes.
According to a fourth aspect of the present invention, in the automatic door system of the first aspect, the control portion further obtains a plurality of positions of the passer at a plurality of times to detect a moving direction of the passer on the basis of the plurality of positions.
According to a fifth aspect of the present invention, in the automatic door system of the fourth aspect, the control portion further detects a moving speed of the passer on the basis of the plurality of times and the plurality of positions.
A sixth aspect of the present invention is directed to an automatic door system comprising: first and second doors located sequentially; and a control portion for detecting an opening and closing state of the first door and determining whether to allow a passer that is passing through the first door toward the second door, to pass through the second door or not on the basis of the opening and closing state of the first door.
In the automatic door system of the first aspect, as to a passer whose moving direction is predictable from a direction that he faces, the control portion predicts whether the passer is moving to the door or not by detecting the direction that the passer faces with respect to the door. Thus, the control portion opens the door only when the passer that is moving to the door is detected. In other cases, the control portion does not open the door. This suppresses unnecessary operation of the door as compared with a case where the door is opened every time a passer approaches the door.
In the automatic door system of the second aspect, the control portion measures the width of a passer along the second axis, the width being different depending on the direction that the passer faces. This allows the control portion to detect a direction that the passer faces with respect to the door.
In the automatic door system of the third aspect, the control portion obtains variance of a projection of a passer when the passer is viewed from a direction along the fourth axis, the variance of a projection obtained when the passer is viewed obliquely from above being different depending on the direction that the passer faces. This allows the control portion to detect a direction that the passer faces with respect to the door.
In the automatic door system of the fourth aspect, the control portion not only predicts the moving direction of a passer from the direction that the passer faces but also detects the actual moving direction of the passer. Thus, the control portion opens the door only when the passer that is actually moving along the first axial is detected. In other cases, the control portion does not open the door. This further suppresses unnecessary operation of the door.
In the automatic door system of the fifth aspect, the control portion detects the moving speed of a passer when the passer is actually moving along the first axis. This allows the control portion to open the door opportunely depending on the moving speed.
In the automatic door system of the sixth aspect, the operation portion opens the second door after recognizing the closing of the first door which has once been opened for a passer moving to the second door. This prevents the first and the second doors from opening at the same time.
Thus, it is an object of the present invention to provide an automatic door system and a method for controlling an automatic door which prevent the automatic door from being opened when a stationary object is just placed in the vicinity of the entrance of the automatic door or when a passerby just passes by the entrance of the automatic door.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.